'What, fewer than 2? Doesn't seem that bad to me.'
Before he launches into a diatribe along the lines of
"In my day, we had to lay the fiber first, then create the damn Web page ourselves, before writing out the HTTP GET by hand ... twice for good measure. And WiFi, wouldn't we have just killed for Wi-Bloody-Fi, we hand delivered IP packets, uphill both ways!"
I change the subject and ask him what he thinks about the Liberal party. A different diatribe follows.
As far as I know, Dad has 2 account names (and associated passwords), one for his email provider, another for banking.
Without numbers to back me up, I would hazard a guess that the distribution of '# of distinct online identities' follows a power law, like the distribution of connections in a social network, or of links to identity blogs - there are a few with many, but many with few.
I double posit that 20% of online people have 80% of the total number of identities, or some other pair of similarly skewed numbers that add up to 100, you choose).
Some of course wallow in the Long Tail.